Anaplastic mixed gliomas and anaplastic oligodendroglioma in children: results from the CCG 945 experience.

PURPOSE: To review interpathologist diagnosis variability and survival of children treated for either anaplastic mixed glioma (AMG) or anaplastic oligodendroglioma (AO) with surgery, irradiation and chemotherapy. PATIENTS AND METHODS: Two hundred and fifty patients with an institutional diagnosis of malignant glioma were enrolled on Children's Cancer Group CCG-945 between 1985 and 1991, and administered vincristine during involved field radiotherapy, then six cycles of prednisone, lomustine and, vincristine; or two cycles of "eight-drugs-in-one-day" (8-in-1) chemotherapy then involved-field radiotherapy followed by six cycles of 8-in-1 chemotherapy. Central review of institutional pathology was post hoc by five experienced neuropathologists. RESULTS: Twenty-six children had institutional diagnoses of AMG and four had AO. Complete resection and cerebral tumor location was associated with better overall survival (OS) in patients with institutional diagnoses of AMG. However, central review established that only nine of 26 children had AMG: either mixed oligoastrocytoma (MOA) or anaplastic mixed oligoastrocytoma (AOA) and only one had AO. Central review revealed five more patients with AMG, but none with AO. Institutional and CCG central review diagnoses of AMG or AO had poor Jaccard reliabilities of 0.29 and 0.25 respectively. Five-year EFS and OS for five children with centrally confirmed MOA was 50 +/- 20%, with four centrally confirmed AOA was 37.5 +/- 17%. After central review, small samples made tests for differences in survival between regimes impossible. CONCLUSION: Diagnosis of these tumors is challenging, with only 35% of institutional diagnoses confirmed for AMG and 25% for AO, and survival among children with these tumors is poor, despite intensive therapy. This suggests reliable diagnostic markers and new therapeutic approaches are needed.

Precancerous stem cells have the potential for both benign and malignant differentiation.

Cancer stem cells (CSCs) have been identified in hematopoietic and solid tumors. However, their precursors-namely, precancerous stem cells (pCSCs) -have not been characterized. Here we experimentally define the pCSCs that have the potential for both benign and malignant differentiation, depending on environmental cues. While clonal pCSCs can develop into various types of tissue cells in immunocompetent mice without developing into cancer, they often develop, however, into leukemic or solid cancers composed of various types of cancer cells in immunodeficient mice. The progress of the pCSCs to cancers is associated with the up-regulation of c-kit and Sca-1, as well as with lineage markers. Mechanistically, the pCSCs are regulated by the PIWI/AGO family gene called piwil2. Our results provide clear evidence that a single clone of pCSCs has the potential for both benign and malignant differentiation, depending on the environmental cues. We anticipate pCSCs to be a novel target for the early detection, prevention, and therapy of cancers.

Outcome of children with centrally reviewed low-grade gliomas treated with chemotherapy with or without radiotherapy on Children's Cancer Group high-grade glioma study CCG-945.

BACKGROUND: The objectives of the current study were to determine the outcome of children who were treated with chemotherapy and radiotherapy on the Children's Cancer Group (CCG) high-grade glioma protocol (CCG-945) who were diagnosed with low-grade gliomas on post hoc central pathologic review and to identify clinical and biologic features associated with prognosis. METHODS: Between 1985 and 1991, 250 children with institutionally classified high-grade gliomas were enrolled on CCG-945. Patients older than 24 months with intracranial lesions were assigned randomly to receive either lomustine, vincristine, and prednisone (control regimen) or the 8-drugs-in-1-day regimen (experimental regimen); younger patients and those with primary spinal cord tumors were assigned nonrandomly to the experimental regimen. Central independent review by 5 neuropathologists led to a reclassification of low-grade glioma in 70 patients, who were the focus of the current study. RESULTS: The study involved 42 males and 28 females (median age, 7.7 years) with a median follow-up of 10.4 years. At 5 years, the progression-free survival (PFS) rate was 63% +/- 6%, and the overall survival (OS) rate was 79% +/- 5%, compared with a PFS rate of 19% +/- 3% (P < 0.0001) and an OS rate of 22% +/- 3% (P < 0.0001) in the remainder of the cohort. Significantly poorer 5-year PFS was seen in children younger than 24 months, those with fibrillary astrocytoma, and those with posterior fossa tumors. Patients demonstrated a modest improvement in PFS but no improvement in OS compared with children with low-grade gliomas who were treated with contemporary chemotherapy-alone approaches. CONCLUSIONS: The current report calls attention to the importance of central pathologic review in large multiinstitutional trials of children with gliomas and suggests that aggressive front-line combined chemoradiotherapy does not confer a survival advantage in this highly selected population of patients.